Electrocardiography (ECG) is the process of recording the electrical activity of the heart over a period of time using an arrangement of electrodes placed on a patient's body. These electrodes detect electrical changes on the skin that arise from the heart muscle depolarizing during each heartbeat. There are various lead configurations having corresponding electrode placements that can be used to perform electrocardiography (e.g., 12-lead ECG). The waveforms in ECG signals can be printed on paper or visualized on a display for interpretation and analysis.